It is well known that routine oil changes will prolong engine life and performance. With use, motor oil accumulates suspended particles from the atmosphere, from engine parts wearing against one another, and from the products of incomplete combustion. The particles in turn cause abrasive wear of the engine bearings, piston rings, and other moving parts. This adversely affects the engine and, if left uncorrected, can destroy the engine.
To maintain proper engine effectiveness, regular changing of the motor oil in an internal combustion engine is a required task. In currently designed vehicles, the oil pan acts as a reservoir for distribution of engine oil. Engine lubrication is generally provided through a gear-type pump. The pump draws engine oil from the oil pan sump, after which the oil is passed from the pump to the oil filter. The oil filter is generally comprised of pleated synthetic, cellulose paper, fiberglass or other non-woven, synthetic media. In some applications, an oil filter bypass valve is used to ensure adequate oil supply should the filter become blocked or develop excessive pressure drop. In addition, an anti-drainback valve is often provided to prevent backflow of oil. Oil is channeled through the filter to the main valve train components, cam shaft bearings, rocker arms, hydraulic lifters, rod bearings, and other main components of the engine requiring lubrication. A pressure regulator valve, sometimes located in the oil pump, maintains appropriate pressure for the lubrication system and bypasses any excess back to the suction side of the pump. Oil from the pump passes through the filter before going to the main engine parts. In the filter, the oil passes through a filter element where dirt and foreign particles are extracted. To eliminate the used oil, the drain plug, generally located in the lower portion of the oil pan, is opened. The used oil containing suspended particles is allowed to flow by gravity out of the pan into a suitable receptacle. After the used oil is withdrawn, the plug is replaced and fresh oil is added to the engine, usually through a separate aperture in the engine valve cover. As the oil is withdrawn, the oil filter is normally removed, discarded and replaced with a new filter to be used with the fresh oil change. However, the filter and the material of which it is constructed, is capable of a much longer life of service if the filter material can be cleaned of accumulated residue.
One such attempt to clean the oil filter is disclosed in U.S. Pat. No. 2,919,704 issued to Butler on Jan. 5, 1960. In the Butler device, the oil filter is placed in a cleaning compartment and compressed air passing through a venturi is used to draw cleaning fluid into the used filter. The liquid, in combination with the air, cleans the filter. After a sufficient time to clean the filter and the filtering material, a valve is closed to stop the flow of cleaning liquid and compressed air will continue to pass upwardly through the jet nozzle to dispel all liquid from the filter and its filtering material so that the filter may be completely dried before it is removed from its cleaning compartment.
A similar oil filter cleaner is set forth in U.S. Pat. No. 3,044,475 issued to Thompson on Jul. 17, 1962. The Thompson patent provides an external cleaning apparatus wherein a centrally bored head is connected to one end of a conventional tank-type oil filter. Compressed air is introduced such that the directional flow is opposite the normal filtering flow of fluid through the filter. After the majority of the oil contained by the filter is blown out, certain valves are opened and closed to admit cleaning fluid from a reservoir to enter and fill the filter. The filter and head are pivoted to an inverted position and valves are operative to blow the cleaning fluid out of the filter.
In both Butler and Thompson, a separate cleaning liquid or fluid is required to purify the oil filter. In addition, both devices utilize auxiliary components external to the filter for cleaning fluid purposes once the oil filter has been disconnected from its internal combustion engine. It is further clear that in both Thompson and Butler, the function of the compressed air is to dry the filter and to transport the cleaning fluid. Because the normally provided oil inlet and oil outlet are used to introduce and drain air and cleaning fluid in a reversible direction, neither Butler's nor Thompson's device can be used for oil filters having anti-drainback valves.
U.S. Pat. No. 5,051,173 issued to Hoelzel on Sep. 24, 1991, discloses a device to remove oil from an oil filter which has been disconnected from an internal combustion engine. In this device, an external air inlet is used to blow pressurized air through the normal oil outlet of an inverted oil filter such that contaminated oil is exhausted through the normal oil inlet and into a bucket or container for collecting the oil. The purpose of this device is simply to eliminate oil from the oil filter before it is discarded. This apparatus has the same shortcomings as previously discussed in Butler and Thompson, namely, that the oil filter must be removed from its installation and that auxiliary equipment must be used to exhaust oil from the filter. In addition, no consideration is given in Hoelzel for controlling the pressure of the compressed air such that the filter element will not be damaged.
Accordingly, it is especially desirable to provide an in situ, reusable oil filter which is integrally provided with ports which will allow compressed air to enter and contaminated oil to drain from the filter housing. Such filter should be able to be installed directly on an apparatus such as an internal combustion engine without the need for separate adapters or auxiliary components, regardless of the type of filter being used. The cleanable oil filter should contain an appropriately sized channel to restrict the airflow, allowing cleaning of the filter element without damage to it, the filter housing, or the apparatus. It is further desirable that the cleanable oil filter utilize only air and residual oil to clean the filter and eliminate time consuming drying steps used to previously remove oil and cleaning fluid. It is also desirable that the cleanable oil filter utilize only air and residual oil to clean the filter since less waste is generated and needs to be disposed of relative to prior art arrangements requiring a separate cleaning fluid or backwashing only with oil.